package com.juc.pc;
import java.util.Objects;
import	java.util.concurrent.locks.Condition;
import	java.util.concurrent.locks.ReentrantLock;

import java.util.concurrent.locks.Lock;

public class B {
    public static void main(String[] args) {
        Data2 data = new Data2();
        new Thread(()->{
            for (int i = 0 ; i < 10; i++) {
                try {
                    data.increment();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"A").start();

        new Thread(()->{
            for (int i = 0 ; i < 10; i++) {
                try {
                    data.decrement();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"B").start();

        new Thread(()->{
            for (int i = 0 ; i < 10; i++) {
                try {
                    data.increment();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"C").start();

        new Thread(()->{
            for (int i = 0 ; i < 10; i++) {
                try {
                    data.decrement();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"D").start();
    }

}

//判断等待，业务，通知
class Data2{ //数字资源
    private int number = 0;

    Lock lock = new ReentrantLock();
    Condition condition = lock.newCondition();

    //condition.await();  //等待
    //condition.signal(); //唤醒全部
    //+1
    public void increment() throws InterruptedException {
        lock.lock();
        try {
            //业务代码
            while (number != 0){
                //等待
                condition.await();
            }
            number++;
            System.out.println(Thread.currentThread().getName() +"=>"+number);
            //通知其他线程，我+1完毕了
            condition.signal();
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            lock.unlock();
        }
    }

    @Override
    public int hashCode() {
        return Objects.hash(lock);
    }

    //-1
    public void decrement() throws InterruptedException {
        lock.lock();
        try {

            //业务代码
            while (number == 0){
                //等待
                condition.await();
            }
            number--;
            System.out.println(Thread.currentThread().getName() +"=>"+number);
            //通知其他线程，我+1完毕了
            condition.signal();
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            lock.unlock();
        }
    }
}


